In the shadow of Louis Kahn's 1972 masterwork, the new pavilion designed by Renzo Piano Building Workshop aims to pay homage to the original, but instead offers a kind of distant defacement.

Pity the museum that finds itself in possession of a masterpiece. Not an artwork—those are great: works like a Duccio and a Michelangelo, the Cézannes and the Picassos, the divine Bohdisattvas and the Ganeshas, all of which can be found in the galleries of the Kimbell Museum of Art in Fort Worth, Texas. No, the problem is when the masterwork is a work of architecture.

Between 1966 and 1972, the Kimbell got the right man at the right time at the right place. Louis Kahn—despite his brief career and with due deference to Frank Lloyd Wright, Louis Sullivan, and Thomas Jefferson—is America’s greatest architect. Beyond any measure of taste or style, Kahn’s best buildings combine, in enduring and astonishing ways, methods and virtues that confound commonplace distinctions—between ancient and modern, natural and artificial, practical and poetical—all with a palpable feeling for the dignities and liberties of their inhabitants. An entire city of this particular perfection, lacking the stimulating misfits of everyday life, would pall. Yet each of Kahn’s few works is a glimpse into an unbroken world.

Richard BarnesAerial view of the campus from the northwest.

Kahn’s Kimbell is iconic: Those rolling cycloid vaults, those porticoes and courts and pools, those hidden skylights and suspended reflectors, and all that silvery daylight they steal from the gods. Those divine proportions and overlaid rhythm of 20-foot vaults and 10-foot service bays, with all their built-in devices and services as integrated and resolved as watchworks, and the travertine and concrete that bring together gloss and grit, intimacy and monumentality, in a way that is just right for a Texas treasure palace whose founding fortune was wrought from livestock feed and oil.

Inseparable from that architectural design, Kahn’s landscape design (developed with George Patton and Kahn paramour Harriet Pattison, now well-known as the mother of My Architect filmmaker Nathaniel Kahn) incorporated century-old trees that had lined a street formerly on the site, mingling in red oaks and elms and aligning grids of crepe myrtles and yaupon hollies with the multilevel platforms and courts and pools that brought together building and plantings—all making, for this car-bound and desert-dusted city, a dappled garden. In a June 1969 letter to patron Kay Kimbell, Kahn described the villa-in-a-garden concept of the building, calling its west garden-facing façade and porticoes the “entrance of the trees.”

The last project Kahn saw completed, that building and its grounds are as much an essential record of a human nature, and of a humanist mission, as the Michelangelo artwork it shelters. And like that painting it should be stewarded in such a way that another 500 years of humankind can fully experience its original effects. If the Kimbell Museum were an insurance company or a car wash, it would face the same ethical duty, but as an institution explicitly concerned with the propagation of aesthetic experience, and with the long durations of conservation and curation, the assignment is closer to home.

Richard BarnesView of the main (west) entrance.

It’s not an easy thing, to have greatness thrust upon you. A little Kahn goes a long way. Familiarity breeds, if not contempt, then a certain situational blindness. Forty years come and go, and a museum’s collection and mission grows. It finds itself in need of additional gallery space. And an education center. And a bigger auditorium. And even more parking. What then? First, a fiasco. Then, Renzo Piano, Hon. FAIA. The fiasco was an aborted 1989 expansion plan, designed by Kahn office veteran Romaldo Giurgola, FAIA, that suggested extruding Kahn’s iconic vaults to the north and south like so much toothpaste—a not-unsupportable proposal given that Kahn’s early schemes for the original building had not dissimilar features, yet one that drew an arts-pages firestorm, and was unceremoniously withdrawn.

Richard BarnesRoof detail on the south canopy, with a view east to the Kahn building beyond.

In 2007, without the usual competitions and consultations, the Kimbell announced a new addition to be designed by Piano. He had done well with small Texas museums, like Houston’s 1986 Menil Collection and Dallas’s 2003 Nasher Sculpture Center—establishing, with his signature louvers and skylights, a reputation for knowing how to daylight a gallery, and for directing the busy traffic of high-end institutions. A formerly prodigious practice that is now merely prolific, Piano’s Building Workshop has produced many buildings of notable efficacy, applying architecturally scaled technology to the programmatic essentials and perfecting an aesthetic of apparent systematicity. New York’s Whitney Museum and the Los Angeles County Museum of Art, after their own failed additions, found in Piano a kind of fixer and controversy-cooler—a signifier of good taste and seeming guarantor of critical approbation, if not unalloyed praise.

Reviews since the November opening of Piano’s addition have been dutiful, mostly of the “two masters meet at the top of their game” variety; or even more decorously, they have followed a narrative of “today’s masterpiece joins yesterday’s and shows admirable deference.” But neither of those tales is especially true. Somewhere between commission and construction, the site of Piano’s freestanding addition got moved from an unimpeachably deferential position across the street from the Kahn’s building’s east entrance, up and over into the garden itself. Piano’s 100,000-square-foot, $132 million building now goes head-to-head against Kahn’s 120,000-square-foot original across less than 200 feet of parking-garage-capping lawn. Kahn’s “entrance of the trees” now faces not old oaks and elms, but the blind concrete wall and antic overhanging canopy that are the main features of the new structure’s front façade.

Richard BarnesExterior view of the east façade and entrance, from the northeast.

Building in Kahn’s garden, next to his villa, one might incline towards two possibilities: A diaphanous architecture of steel and glass that complements-by-contrast with its substantial concrete antecedent, or a grassy berm that, like Piano’s green roof for San Francisco’s California Academy of Sciences or his Paul Klee Center in Bern, Switzerland, becomes part of the garden itself. Piano’s new building does a bit of both, while fully committing to neither.

Richard BarnesLobby, view from the north.

A partially glazed pavilion in front houses a very big lobby (which presumably will be primarily an event space), and some smaller-than-expected temporary exhibition galleries (one sharing space with a generously scaled gift shop) featuring 11-foot-tall reconfigurable partitions and clever air vents in the gaps between the widely spaced floorboards. There’s a berm-like barrow to the back that houses a 300-seat auditorium along with education and support spaces and a low-light gallery. But the barrow, much-incised with loading docks and light wells and parapets, isn’t all that buried.

Richard BarnesSouth gallery, view from the southeast.

And the pavilion isn’t all that glassy. It features a familiar catalog of Piano details: As at the Art Institute of Chicago, there are structural columns that sneak outside the enclosing walls, supporting a thin but deeply overhanging roof; and as at the Nasher, there’s an insistent striation of walls and beams (this time, 10 feet on center, running north–south) that sets up the finer grain above of the glass roof and associated gadgets (this time, operable louvers with solar panels over fritted glass over fabric scrims). The beams are 104 feet long, 4 feet deep, and made from laminated Douglas fir, although their bleached grayish color renders them—especially from that critical 200-foot distance to the Kahn—virtually indistinguishable from the concrete walls below. On the building’s south and north façades, this results in a massive and deeply articulated top for what is, at 23-feet tall, a low-slung building—its miniature monumentality and rusticated modernism reminiscent of a Hugh Stubbins Jr., or a Harry Weese, or a Kevin Roche, FAIA.

Richard BarnesView, from the west, of the passage to main lobby of the Piano pavilion and to the Kahn building beyond.

To his own signature features, Piano appears to have added several direct references to Kahn’s. The two buildings share a tripartite plan, with the meter of Piano’s beams paralleling and equaling the length of Kahn’s vaults, whose profile is distantly referenced by the very slight convex curve of Piano’s skylights. A strip window between the base of those Douglas fir beams and the top of the perimeter concrete wall recalls the similar reveals between Kahn’s vaults and end walls. Paired staircases down to the auditorium and the under-lawn parking vaguely parallel the twinned staircases that famously slip visitors up from the deliberately unpromising east entrance of Kahn’s Kimbell, to the astonishing plenum of gallery and garden above. For some reason, however, one concrete side wall of both sets of Piano’s stairs, and a retaining wall elsewhere, are canted by about 10 degrees. A case could be made that these quasi-Kahnisms pay tribute to their originals next door. But the opposite may also be true: By placing not-quite-duplicates nearby, Piano lessens the effect, in memory and anticipation, of the originals—a kind of distant defacement.

Richard BarnesDouble staircase leading to auditorium.

The “uncanny valley” is that famous zone of experience in which a copy’s approximation of an original is so close and yet so far, so that the distinctions between the two become acutely visible, and causes the whole to be repulsive. It is into this valley that much of Piano’s psuedo-Kahn falls, especially in the significant management of the many mechanical and structural elements—pipes, tubes, beams, frames, reveals, channels, panels, brackets, spacers, sealants—that in Kahn’s building reliably converge into resolved assemblies far greater than the sum of their parts. In Piano’s building, many of these same components complacently compound—clips on clips, tubes on tubes—but by Kahn’s standards they are more coincident than truly convergent: adding and adding, without ever quite adding up. In this, the 23rd museum produced by an admirably busy practice, the resulting quietude may be less the result of restraint than of a finite capacity for taking pains—suggesting less the humility with which Piano’s building has been credited, than a kind of smarm.

Richard BarnesView into the auditorium from the east.

Perhaps the closest analogy to what has happened at the Kimbell is Cabell Hall at the University of Virginia, with which, in 1899, Stanford White closed off the view from the famous Lawn to the distant mountains and Western Frontier at which Jefferson had deliberately directed it—turning a Founding Father’s “architectural commandment” into a mere quadrangle. Kahn’s garden was far more modest, but there’s a lesson in how White’s Beaux-Arts bowdlerizing of Jefferson’s Georgian classicism took much of the thrill and the enlightened strangeness out of its neighboring originals.

Richard BarnesCourtyard, with view to the glazed passage connecting the south and west galleries.

When asked at a November lecture in Fort Worth what he thought of his work at the Kimbell, Piano replied, “We need the trees to grow.” He elaborated, wisely and touchingly, that even the greatest new buildings take time for their rough edges, flaws and features both, to be worn smooth by use, “to become part of the day-to-day life of the city. It needs a patina. … Architecture relies on a long time, it is made real only in time, like forests are.” Yaupon hollies are tolerant and hardy and evergreen. They grow fast. Soon, they and other new plantings may restore something of the proportions and conversations Pattison and Kahn imagined between branches and arches: between museum and garden and city. They may someday moderate the dire tuba-in-the-strings-section presence of the neighboring University of North Texas Health Science Center that, absent big trees, looms over what’s left of the garden.

But for now, those yaupons perform a different kind of miracle: Currently head-height when viewed from the sunlit forecourt at the heart of Kahn’s Kimbell, the trees’ delicate-yet-dense canopies blend seamlessly into the remaining garden landscape, and in a perspectival trick worthy of Duccio or Michelangelo, perfectly align with the elevation of the new building to the west—erasing it, as if it had never come to pass, from view.

Richard BarnesExterior view of the South gallery of the Piano pavilion, at night.

For more on the Renzo Piano Pavilion at the Kimbell Art Museum, including critiques, videos, and photo galleries, click here.